BlackboxMyCar CPL Filter for Blackvue Dashcams Review

We recently paired up with a team of engineering students from Simon Fraser University to develop a CPL filter for some of our Blackvue dash cams. We tried out various designs for the CPL filter and bracket but tested this one to work the best under heat and fit the most securely. This filter is designed to work with older models such as the DR500GW-HD as well as the latest DR650S-2CH, while these models are all similar in size, they have very slight variations in diameter hence why we had to go with a more flexible design. The CPL filter can significantly reduce glare caused by dashboard reflections. These reflections make some details very hard to pick up as the texture of the dashboard and harsh lines get projected over the video footage.

We found the need for the CPL filter more prevalent with newer cars that have more rake-backed windshields. These windshields help with aerodynamics and pedestrian safety but can create much more glare than very upright windows. When the camera is mounted so far back, it catches all the glare and reflections from the dashboard between the lens and windshield. The BlackboxMyCar Ford Fiesta suffers from this quite severely as you can see in the sample footage.

With our CPL filter we found that it reduced the glare significantly and allowed us to configure it to what worked best for the vehicle and camera position. To correctly adjust the CPL filter, we parked with the car facing the sun and activated the live view of the dash cam through the WiFi app. Once the live view was setup, we could rotate the CPL filter to our liking. The CPL filter is attached to the mounting bracket using magnets and can be adjusted to the user's preference.

The downside to running the CPL filter is that at night time the video is a bit darker. With the Blackvue cameras you can increase the brightness to compensate but since less light is going through the lens, there's only so much the sensor can do. It's easy enough to slide the filter off of the camera if needed but in our testing we left it on and still preferred the glare-reducing effects of the filter. At night, street lights can still cause the same sort of reflection as sunlight during the day and the CPL filter can help with that issue. Overall if your vehicle is prone to distracting dashboard reflections, we definitely recommend checking out this CPL filter.